Ice and snow are major enemies of home and business owners across the United States. After every major snow storm, millions of people wake up in the morning only to find their garage doors and driveways blocked by piles of snow. Such cold early mornings start with shoveling of mountains of snow off the driveway, just to get to work. The result is tiredness, lateness to work, and greatly decreased productivity throughout the day. Similarly, countless businesses find their driveways and parking accommodations impassable for motorized and pedestrian traffic for days, and sometimes weeks, after a major snowstorm. All of these minor and major inconveniences translate into billions of dollars in lost profits for our economy. Furthermore, grave legal liability, resulting from slips and falls on wet and ice/snow covered sidewalks and stairwells, is known all too well to business and home owners across the United States.
The most common ways of battling the menace of ice and snow is by physically breaking and shoveling it away from stairs, entrances and passageways. This process is extremely laborious and time-consuming. Old people, young people, and those with imperfect health are often unable to perform this task at all. Gas-powered snow-cleaners exist. But these devices also require considerable effort and skill to operate, can be dangerous to people and animals and destructive to surfaces. Furthermore, much like shoveling, cleaning with gas-powered snow cleaners does not remove the snow, but only displaces it into piles on the side. These piles take weeks to gradually melt. Melted water from the piles, flows back onto sidewalks during the day and turns into solid slippery ice overnight.
Furthermore, attempts to mechanically remove the snow during continuing snowfall are almost always doomed to failure. New layers of falling snow cover the cleaned surfaces within minutes, requiring repeated cleanings. In high traffic areas, additional snow will be brought in on shoe soles and vehicle tires.
Snow and ice-covered surfaces are often treated with sand or salt to reduce slipperiness and melt the precipitation. However, the effects of such treatments on slipperiness are often short-lived, as particles of salt and sand are covered by new precipitation, or frozen into the existing snow and ice. The melting effect is limited to situations when quantities of ice and snow are relatively small and ambient temperature is not much lower than 32 degrees Fahrenheit. The salt and other impurities added to snow, melt it by lowering the melting temperature of water. Thus, if the temperature is significantly lower than 32 degrees Fahrenheit, little if any snow will melt.
Furthermore, large quantities of salt and other chemicals used to melt ice during the winter have a significant negative impact on people and the environment. Salt on the road corrodes automobiles, bridges, and any other metal structures in the vicinity. Salt, sprinkled near houses attracts birds and wild animals, thus increasing the risks of animal-bourne illnesses, such as lime disease. Salt interferes with the growth of vegetation. Salt gets into the ground water and contaminates water supply. Salt is not an ideal deicer.
Another solution to keeping stairways, walkways, and roadways of houses and businesses free of ice and snow, involves the use of under-the surface electrical heating coils. The coils are usually built into the infrastructure or, installed under the stones of walkways. In either case, the installation costs are significant, access is limited, and maintenance of the coils, permanently installed under the surface, is troublesome. The amount of electrical energy, required to heat through and maintain the heat in layers of surface stone is extremely high. The problem of excessive energy use is exacerbated by the fact that under-the-surface coils heat not only the surface above them, but also the ground below. This leads to significant loss of efficiency and, as a result, high energy costs.
A less expensive alternative to under-the-surface heating is in melting mats that are placed flat over the precipitation-covered surface to melt the layers of ice and snow from the top down. Such melting mats usually also comprise electrical heating coils embedded within the mat material. However, such mats exhibit some shortcomings.
For example, heat distribution from heating coils is often uneven. Snow directly under the coils melts faster than that located between the adjacent coils. Since such mats are placed directly on the snow, there is little or no escape for the melted water. There is no circulation of warm water or air over the surface or between the layers of ice and snow. Melting is slow, occurring layer by layer from the top down.
Puddles of cold melted water gather in ditches formed directly under the coils, absorbing the heat and slowing the melting process. Often, such mats are placed in locations, such as under curbs, doorsteps, low lying walkways, and other places, where melted water can not easily escape from the mat. In time, the mat positioned in such a location, will become submerged in a puddle of water. If there are any breaks or tears in the mat's insulation, the water accumulating under or over the mat will cause short circuits, destroying the device and posing significant electrocution risks to users and passers-by.
If snow under the conventional melting mat has successfully melted and the mat is removed, the surface underneath it will be in less-than perfect condition for pedestrian traffic. The surface will be wet and slippery, leading to slips, falls and law suits for businesses and home owners.
Also, much of the heat in over-the-surface mats is lost to the cold air above the mat. Usually both sides of the mat conduct heat. On one hand, double-sided heating is convenient to simultaneously melt the snow below the mat and the snow falling onto the mat from above. However, when there is no immediate snowfall, such double-sided heating results in expensive loss of energy and waste of the efficiency of the mat. To conserve energy and increase efficiency, the mat must have selectable modes for melting the snow above, the snow below, or both simultaneously.
In light of the problems associated with traditional ice melting methods and limitations associated with prior art devices, there is a long-standing and unsatisfied need in the art for a flexible and all-surface adaptable ice melting mat. This mat must be relatively simple and inexpensive to produce and easy to operate. The mat must be safe for pedestrians, allowing for walking upon its surface during use, without presenting the dangers of slippage or electrocution. It must be environmentally-safe and function effectively without releasing any harmful chemicals into the environment. It must be capable of melting ice and snow evenly, quickly and efficiently, with minimal energy expenditures. It must be capable of melting the precipitation below the mat, as well as the snow falling onto the mat from above. The device must also be capable of disposing of, recycling, or evaporating the liquid melt that results from the melting of ice and snow, leaving the surface clean and dry. The present invention achieves all of these objectives and provides numerous additional benefits.